I have spare key for package of these three games. I'm not interested with dota 2, steam cards and similar things. I would like to sell it for 10$. If you really want to exchange it for any game so for this moment i would be interested only with metro last light or new tomb raider.

One thing is giveway, but trading HumbleBundle keys is forbidden on Steam. On a side note...don't you feel bad about it, bartering charity's project for mainstream AA title? Oh wait, I got it! You take it as supersmartninjamovemasterplanthing, right?

P.S. HumbleBundle doesn't necessarily mean 1$...its just cheapskate majority that wants to get max bang (steam keys) with min dough and above it this unscrupulous exploiter breed that wants to profit on it even more, e.g. the OP.